The systems known in art for capturing hydrocarbon fuel vapours that would otherwise be discharged to the atmosphere generally include a canister that processes the fuel vapours created in the fuel tank during refueling, heat expansion and other activities. The canister generally includes activated charcoal or similar material to adsorb and temporarily store the fuel vapour. After an interval of collecting fuel vapour in the canister, the fuel vapour is purged during a purging cycle by venting fresh air through the canister to the engine's intake manifold.
Such a prior art design is for example taught in U.S. Pat. No. 5,024,687 issued Jun. 18, 1991 to Waller for use in automobiles, which is incorporated herein by reference. The Waller design has a canister attached via a hose to the refuelling hose. When the engine is in operation, a purge flow control means is opened to allow a flow of air and fuel vapour to pass from the canister to the engine intake manifold.
The prior art design, as exemplified by Waller, requires a large external vapour canister, occupying space within the body of the vehicle. Such a design also requires separate vapour lines into and out of the vapour canister.
It is therefore desirable to have an apparatus that captures fuel vapour without requiring a bulky external canister with multiple vapour lines.